FreeBSD Man Pages

RL(4) FreeBSD Kernel Interfaces Manual RL(4)
NAMErl -- RealTek 8129/8139 fast ethernet device driver
SYNOPSISdevicerlDESCRIPTION
The rl driver provides support for PCI ethernet adapters and embedded
controllers based on the RealTek 8129 and 8139 fast ethernet controller
chips. This includes the Allied Telesyn AT2550, Farallon NetLINE 10/100
PCI, Genius GF100TXR, NDC Communications NE100TX-E, OvisLink LEF-8129TX,
OvisLink LEF-8139TX, Netronix Inc. EA-1210 NetEther 10/100, KTX-9130TX
10/100 Fast Ethernet, Encore ENL832-TX 10/100 M PCI, Longshine
LCS-8038TX-R, the SMC EZ Card 10/100 PCI 1211-TX, and various other cheap
adapters. It also supports the Accton EN1207D which has a chip labeled
MPX5030 (or MPX5038) which appears to be a RealTek workalike.
The RealTek controllers use bus master DMA but do not use a descriptor-
based data transfer mechanism. The receiver uses a single fixed size
ring buffer from which packets must be copied into mbufs. For transmis-
sion, there are only four outbound packet address registers which require
all outgoing packets to be stored as contiguous buffers. Furthermore,
outbound packet buffers must be longword aligned or else transmission
will fail.
The 8129 differs from the 8139 in that the 8139 has an internal PHY which
is controlled through special direct access registers whereas the 8129
uses an external PHY via an MII bus. The 8139 supports both 10 and
100Mbps speeds in either full or half duplex. The 8129 can support the
same speeds and modes given an appropriate PHY chip.
The rl driver supports the following media types:
autoselect Enable autoselection of the media type and options.
This is only supported if the PHY chip attached to
the RealTek controller supports NWAY autonegotia-
tion. The user can manually override the autose-
lected mode by adding media options to the
/etc/rc.conf file.
10baseT/UTP Set 10Mbps operation. The mediaopt option can also
be used to select either full-duplex or half-duplex
modes.
100baseTX Set 100Mbps (fast ethernet) operation. The
mediaopt option can also be used to select either
full-duplex or half-duplex modes.
The rl driver supports the following media options:
full-duplex Force full duplex operation
half-duplex Force half duplex operation.
Note that the 100baseTX media type is only available if supported by the
adapter. For more information on configuring this device, see
ifconfig(8).
DIAGNOSTICSrl%d:couldn'tmapmemory A fatal initialization error has occurred.
rl%d:couldn'tmapinterrupt A fatal initialization error has occurred.
rl%d:watchdogtimeout The device has stopped responding to the network,
or there is a problem with the network connection (cable).
rl%d:nomemoryforrxlist The driver failed to allocate an mbuf for
the receiver ring.
rl%d:nomemoryfortxlist The driver failed to allocate an mbuf for
the transmitter ring when allocating a pad buffer or collapsing an mbuf
chain into a cluster.
rl%d:chipisinD3powerstate--settingtoD0 This message applies
only to adapters which support power management. Some operating systems
place the controller in low power mode when shutting down, and some PCI
BIOSes fail to bring the chip out of this state before configuring it.
The controller loses all of its PCI configuration in the D3 state, so if
the BIOS does not set it back to full power mode in time, it won't be
able to configure it correctly. The driver tries to detect this condi-
tion and bring the adapter back to the D0 (full power) state, but this
may not be enough to return the driver to a fully operational condition.
If you see this message at boot time and the driver fails to attach the
device as a network interface, you will have to perform second warm boot
to have the device properly configured.
Note that this condition only occurs when warm booting from another oper-
ating system. If you power down your system prior to booting FreeBSD,
the card should be configured correctly.
SEE ALSOarp(4), miibus(4), netintro(4), ng_ether(4), polling(4), ifconfig(8)TheRealTek8129and8139datasheets, ftp.realtek.com.tw:/lancard/data
sheet.
HISTORY
The rl device driver first appeared in FreeBSD 3.0.
AUTHORS
The rl driver was written by Bill Paul <wpaul@ctr.columbia.edu>.
BUGS
Since outbound packets must be longword aligned, the transmit routine has
to copy an unaligned packet into an mbuf cluster buffer before transmis-
sion. The driver abuses the fact that the cluster buffer pool is allo-
cated at system startup time in a contiguous region starting at a page
boundary. Since cluster buffers are 2048 bytes, they are longword
aligned by definition. The driver probably should not be depending on
this characteristic.
The RealTek data sheets are of especially poor quality, and there is a
lot of information missing particularly concerning the receiver opera-
tion. One particularly important fact that the data sheets fail to men-
tion relates to the way in which the chip fills in the receive buffer.
When an interrupt is posted to signal that a frame has been received, it
is possible that another frame might be in the process of being copied
into the receive buffer while the driver is busy handling the first one.
If the driver manages to finish processing the first frame before the
chip is done DMAing the rest of the next frame, the driver may attempt to
process the next frame in the buffer before the chip has had a chance to
finish DMAing all of it.
The driver can check for an incomplete frame by inspecting the frame
length in the header preceding the actual packet data: an incomplete
frame will have the magic length of 0xFFF0. When the driver encounters
this value, it knows that it has finished processing all currently avail-
able packets. Neither this magic value nor its significance are docu-
mented anywhere in the RealTek data sheets.
FreeBSD 10.1 November 24, 2004 FreeBSD 10.1